Demolition crews have brought down large sections of a heritage-listed Surry Hills building that was destroyed by an out-of-control fire on Thursday.
Hundreds of bricks tumbled down as a sixty-tonne excavator tore through the remaining unstable structures.
Onlookers who gathered to watch the former factory crumble gasped as a large portion of the wall fell to the ground.
A drone was also deployed to oversee the destruction of the heritage-listed site.
NSW Fire and Rescue Superintendent Adam Dewberry said work had finished for the day, and would recommence tomorrow.
He said a platform needed to be built over the rubble in the laneway, to gain access to the building's back wall.
Robert Silberberg has lived for 18 years in an apartment that faces the historic building.
"As you can imagine, this building's been my next door neighbour for the entire time that I've been living here," he said.
"It's just extraordinary to see it turned into a smoking ruin."
Experts say the building's walls have moved 70mm since the blaze destroyed the heritage-listed site on Thursday.
Fire and Rescue NSW Superintendent Adam Dewberry said it appears there was no asbestos in the building.
"We're on top of the fire, although we're still concerned with the deep-seated fire in the basement area," Mr Dewberry said.
"A lot of work has to be done in a compressed time frame here, but we are progressing through that now."
The superintendent said his team is trying to get the community back on track.
"Our priority is to get people back in their homes, businesses up and trading, and roads open as soon as possible."
Search for potential bodies
Once the building site is secure, rubble will be removed, and the arson squad will send in cadaver-detection dogs to search for any human remains.
Two people believed to have been sleeping rough in the former hat factory have not yet been accounted for.
Detective Superintendent Gordon Arbiinja said on Monday he could not rule out whether there was anyone under the rubble.
"I don't have their identities," he said.
"I just have a description of them, but we need to do the best we can do to account for these people."
Fourth teenager comes forward
Police said a fourth teenager has been identified and spoken to in relation to the fire.
It comes after a 12-year-old, and two 13-year-old boys, began assisting police with their inquiries from Friday.
"We are aware of a further three or four other people who were present during the fire," said NSW Police Acting Assistant Commissioner Paul Dunstan.
"We ask them to come forward with their parents and put their side of the story forward."
No charges have yet been laid, and inquiries are ongoing.